This invention concerns an extra locking element for round plugs. Such plugs may be in the form of plug connectors or receptacles which are made of a punched metal part and optionally may be equipped with overtravel.
Round plugs have a prong part or soldered part to which a cylindrical rolled base part is connected, and said base part is in turn connected either to spring arms with a plug receptacle or a plug pin.
The round plugs usually have stop spring arms which engage corresponding stop edges in a housing compartment after the plugs have been inserted into a housing compartment. If the round plugs are equipped with overtravel, then according to a recent proposal, the stop spring arms may be loacted on the overtravel.
In addition to these stop mechanisms, a plug boundary edge or a similar element may be located in the housing compartment so that a ring-shaped bead on the base part of the round plug comes to rest against this plug boundary edge so the depth to which the round plug can be inserted into the compartment is limited in this way.
In addition, there are also known locking attachments for plugs in which a locking element in the housing compartment catches behind an edge on the plug.
The known means for additional locking of an electric plug, such as a flat spring plug, are not suitable for round plugs because their location is not fixed with regard to their longitudinal axis when the plugs are plugged in, i.e., they may also be rotated about the longitudinal axis while plugged in.